WO2023064000A1

WO2023064000A1 - Charging member with coating layer

Info

Publication number: WO2023064000A1
Application number: PCT/US2022/028300
Authority: WO
Inventors: Noriaki Kuroda; Toru Ozawa
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2021-10-14
Filing date: 2022-05-09
Publication date: 2023-04-20
Also published as: JP2023058944A

Abstract

A charging member includes a conductive support, and a conductive body mounted on the conductive support. The conductive body includes an elastic layer located on the conductive support, a resin layer located on the elastic layer, and a coating layer located on the resin layer. The coating layer contains polysiloxane having a molecular structure having a Si-O-Ti bond and a TiO_4/1unit.

Description

CHARGING MEMBER WITH COATING LAYER

BACKGROUND

[0001] Some image forming apparatuses include a photoreceptor, a charging device, an exposure device which forms an electrostatic latent image on the photoreceptor, a development device which applies a toner onto the electrostatic latent image to develop a toner image, and a transfer device to transfer the toner image formed on the photoreceptor to a transfer material. The charging device includes a charging member to charge the photoreceptor.

BRIEF DESCRIPTION OF DRAWINGS

[0002] FIG. 1 is a schematic cross-sectional view of an example charging member.

FIG. 2 is a schematic cross-sectional view illustrating an enlarged portion of the example charging member of FIG. 1 .

DETAILED DESCRIPTION

[0003] Hereinafter, examples of a charging member will be described with reference to the drawings. In the following description, with reference to the drawings, the same reference numbers are assigned to the same components or to similar components having the same function, and overlapping description is omitted. In the present disclosure, a "range” may in some examples, correspond to an open interval that is defined by a minimum value or by a maximum value, or may in other examples, correspond to a closed interval defined by both a minimum value and a maximum value. In addition, the dimensional ratio of each constituent is not limited to the illustrated ratio. In addition, a value noted with "approximately'' indicates a range including the value and the vicinity of the value. Accordingly, the value indicated with "approximately", in some examples, may correspond to the exact value (excluding "approximately"). In addition, a numerical range indicated by using "to" indicates a range including numerical values before and after "to" as the minimum value and the maximum value, respectively.

[0004] Charging Member and Image Forming Apparatus

An example charging member includes a conductive support and a conductive body mounted on the conductive support. The conductive body includes an elastic layer located on the conductive support, a resin layer located on the elastic layer, and a coating layer located on the resin layer. The coating layer forms the outermost surface of the charging member and contains polysiloxane having a molecular structure having a Si-O-Ti bond and a TIO4/1 unit. Here, the TICU/i unit is a constituent unit having four oxygen (O) atoms and a titanium (Ti) atom which is directly bonded to the O atom, in which two of four O atoms function as a bonding hand and are bonded to the other constituent unit. The remaining two O atoms are not bonded to the other constituent unit, but are bonded to a monovalent organic group.

[0005] The charging member is used by pressing the surface (the outermost surface) thereof against the surface of a photoreceptor. During use, an external additive may attach (or adhere) to the surface of the charging member, so as to contaminate the charging member. For example, in a case where the surface of the charging member is a soft layer, the contamination due to the external additive is more likely to occur. On the other hand, in a case where a surface of the charging member is excessively hard, a crack is likely to occur on the surface. In the example charging device, since the coating layer containing the polysiloxane having the molecular structure having the Si-O-Ti bond and the TiO</i unit forms the surface of the charging member to be in contact with the photoreceptor, the surface is imparted with flexibility (toughness or tenacity) in which a crack is less likely to occur and with sufficient hardness (elastic modulus). Accordingly, the example charging member described above, is configured to suppress the contamination due to the external additive, and to suppress the formation of a crack (for example, the formation of a crack that is likely to occur due to cyclic deformation of compression and extension that is exerted on a contact portion of the charging member with the photoreceptor (e.g., at a nip portion), in low temperature low humidity environment, e.g., 15°C x 10%RH), and image defects due to such crack, so as to impart the charging member with a charging evenness for a longer period of time.

[0006] It is assumed that since two of four O atoms in the TiCU/i unit are not bonded to the other constituent unit, a partial structure (a two-dimensional structure of metal alkoxide) with a high freedom degree and an easy movement (e.g., increased mobility of the molecular structure) can be more easily obtained, compared to a SiO4/2 unit configuring a general polysiloxane, and that the above-described polysiloxane having such a partial structure thereby provides the example charging member with the effect described above.

[0007] Hereinafter, examples of the charging member will be described with reference to an example charging roller 10 illustrated in FIG. 1.

[0008] The example charging roller (which corresponds to the example charging member) 10 includes a conductive body 5, and a conductive support 1 that forms a rotation axis for the conductive body 5. The conductive body 5 is in the shape of a roller to rotate about a rotation axis line (e.g., a center axis) L of the conductive support 1 . The conductive body 5 is rotationally symmetric about the rotation axis line I..

[0009] The conductive body 5 includes a conductive base 6 including an elastic layer 2 that is in contact with the outer circumferential surface of the conductive support 1 and a resin layer 3 that is in contact with the outer circumferential surface of the elastic layer 2, and a coating layer 4 that is in contact with the outer circumferential surface of the resin layer 3. The elastic layer 2 and the resin layer 3 have conductivity. Therefore, the elastic layer 2 may be referred to as a conductive elastic layer, and the resin layer 3 may be referred to as a conductive resin layer. The coating layer 4 is a layer formed by coating and has insulating properties. Therefore, the coating layer 4 may be referred to as an insulating coating layer.

[0010] The resin layer 3 may be located around the elastic layer 2 via other layers. For example, an intermediate layer such as a resistance adjustment layer for increasing voltage resistance (leakage resistance) may be interposed between the elastic layer 2 and the resin layer 3.

[0011 ] The coating layer 4 may be located around the resin layer 3 via the other layers. However, an oriented state of a polymer (e.g., polysiloxane) forming the coating layer 4 may be changed in accordance with the type of layer that is in contact with the coating layer 4, and thus, a physical state (e.g., an irregular state) and chemical properties (e.g., surface free energy or the like) of the outermost surface may be changed. In a case where the coating layer 4 is formed to be directly in contact with the outer circumferential surface of the resin layer 3, contamination on the surface of the conductive body 5 due to the contact with a photoreceptor (for example, contamination due to an external additive) is more easily suppressed.

[0012] Conductive Support

The conductive support 1 may be any suitable conductive support that is formed of a metal having conductivity. In some examples, the conductive support 1 may be a hollow body (e.g., in the shape of a pipe or of a circular tube), a solid body (e.g., in the shape of a rod), or the like that is formed of a metal including iron, copper, aluminum, nickel, stainless steel, and the like. The outer circumferential surface of the conductive support 1 may be subjected to a plating treatment, in order to rustproof the conductive support 1 , or to impart scratch resistance to the extent that the conductivity is not impaired. In addition, the outer circumferential surface of the conductive support 1 may be coated with an adhesive agent, a primer, or the like, in order to increase adhesiveness with respect to the elastic layer 2. In such cases, the adhesive agent, the primer, or the like may be selected to provide a suitable conductivity, in order to increase the conductivity of the conductive support 1 .

[0013] The conductive support 1 may be in the shape of a cylinder having a length of approximately 250 mm to 360 mm. A portion of the conductive support 1 that is covered with the elastic layer 2 may be formed into the shape of a cylinder or a circular tube that extends along a rotation axis line L direction of the conductive support 1 (e.g., an extending direction of the conductive support 1 ), and may have a diameter (e.g., an outer diameter) that is constant in the rotation axis line L direction (in the shape of a straight cylinder or a straight circular tube). The diameter of the portion of the conductive support 1 that is covered with the elastic layer 2 may be approximately 8 mm or more, and may be approximately 10 mm or less. [0014] A portion of the conductive support 1 that is not covered with the elastic layer 2, namely, opposite end portions of the conductive support 1 are supported by a support member. In some examples, the diameter of the portion of the conductive support 1 that is not covered with the elastic layer 2 may be less than the diameter of the portion that is covered with the elastic layer 2. The conductive support 1 rotates about the rotation axis line L of the conductive support 1 , in a state of being supported on the support member.

[0015] The conductive support 1 is biased (or urged) toward a photoreceptor such that the surface of the coating layer 4 is in contact with the surface of the photoreceptor. Namely, in order to push the surface of the coating layer 4 against the surface of the photoreceptor, respective loads may be applied to the opposite end portions of the conductive support 1 toward the photoreceptor. In order to achieve a more suitable coherence of the charging roller 10 with respect to the rotating photoreceptor, a load to be applied to each of the end portions of the conductive support 1 , may be approximately 450 g or more, and may be approximately 750 g or less.

[0016] Elastic Layer

The elastic layer 2 has a suitable elasticity in order to provide uniform cohesiveness with respect to the photoreceptor. The elastic layer 2 may be formed by using: natural rubber; synthetic rubber such as ethylene-propylene- diene rubber (EPDM), styrene-butadiene rubber (SBR), silicone rubber, a polyurethane-based elastomer, epichlorohydrin rubber, isoprene rubber (IR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), hydrogenated NBR (H-NBR), and chloroprene rubber (CR); a synthetic resin such as a polyamide resin, a polyurethane resin, and a silicone resin; and the like. Namely, the elastic layer 2 may include an elastic body containing such base polymers or cross-linked bodies thereof. A single type of the materials may be used in some examples, or two or more types thereof may be used in combination in other examples. In order to achieve a more uniform cohesiveness with respect to the photoreceptor, the base polymer may contain a rubber component (natural rubber or synthetic rubber) as a main component. The base polymer may contain approximately 50 mass% or more of the rubber component, and may contain approximately 80 mass% or more of the rubber component.

[0017] In the base polymer, additives such as a conductive agent, a vulcanizing agent, a vulcanization promoter, a lubricant, and an auxiliary agent may be suitably compounded in order to impart suitable properties to the elastic layer 2. In order to form a more stable resistance, the elastic layer 2 (the elastic body) may contain epichlorohydrin rubber and a cross-linked body thereof as a main component. The elastic layer 2 may contain approximately 50 mass% or more of epichlorohydrin rubber or the crosslinked body thereof, and may contain approximately 80 mass% or more of epichlorohydrin rubber or the cross-linked body thereof.

[0018] Examples of the conductive agent include carbon black, graphite, potassium titanate, iron oxide, conductive titanium oxide (c-TiOa), conductive zinc oxide (c-ZnO), conductive tin oxide (c-SnCh), quaternary ammonium salt, and the like. Sulfur and the like may be used as the vulcanizing agent. Tetramethyl thiuram disulfide (CZ) and the like may be used as the vulcanization promoter. A stearic acid and the like may be used as the lubricant. Zinc flower (ZnO) and the like may be used as the auxiliary agent. [0019] The thickness of the elastic layer 2 may be approximately 1 .25 mm or more, and may be approximately 3.00 mm or less, in order to exhibit suitable elasticity.

[0020] Resin Layer

The resin layer 3 is a layer containing a resin. The resin layer 3 is a layer harder than the elastic layer. For example, an elastic modulus of the resin layer 3 that is measurable on the basis of JIS K7162 is greater than the elastic modulus of the elastic layer. The resin layer 3 is located on the elastic layer 2, so as to suppress the bleeding of a plasticizer or the like from the elastic layer 2 to the surface of the conductive body 5.

[0021] The resin layer 3 may form an irregular surface. Namely, the outer circumferential surface of the resin layer 3 may have an irregularity due to the resin layer 3. In a case where the resin layer 3 forms the irregular surface, the coating layer covers the irregular surface, and thus, the surface of the conductive body has an irregularity. Consequently, a discharge point can be sufficiently provided, and image quality can be improved. On the other hand, in a case where the surface of the conductive body has an irregularity, a crack is likely to form in the vicinity of a boundary between a convex portion and a concave portion on the surface. In the example charging roller 10, the surface is covered with the coating layer containing the polysiloxane described above, and thus, a crack is less likely to form, so as to suppress consequences of the formation of such crack.

[0022] The resin layer 3, with reference to FIG. 2, may contain a matrix material 30, and particles dispersed in the material. In FIG. 2, the particles include first particles 31 , and second particles 32 having a type different from that of the first particles 31. In FIG. 2, the resin layer 3 forms the irregular surface by containing the particles. In the present disclosure, such different types of particles refer to particles having different materials, different shapes, and the like. For example, even in a case where the material of the first particles 31 and the material of the second particles 32 are identical to each other, the first particles 31 and the second particles 32 are considered to be of different types when the shapes thereof are different from each other. In other examples, the particles contained in the resin layer 3 may be of a same type (e.g., one type of particles), or may be of three or more types of particles. [0023] The matrix material 30 may contain a base polymer. For example, a polymer such as a fluorine resin, a polyamide resin, an acrylic resin, a nylon resin, a polyurethane resin, a silicone resin, a butyral resin, a styrene- ethylene-butylene-olefin copolymer (SEBC), and an olefin-ethylene- butyleneolefin copolymer (CEBC) may be used as the base polymer. A single type of the materials may be used in some examples, or two or more types thereof may be used in combination in other examples. In order to increase ease of handling or the like, the base polymer may be of at least one type selected from the group consisting of a fluorine resin, an acrylic resin, a nylon resin, a polyurethane resin, and a silicone resin according to some examples, or may be of at least one type selected from the group consisting of a nylon resin and a polyurethane resin according to other examples.

[0024] The content of the base polymer in the resin layer 3 may be approximately 30 mass% or more, and may be approximately 90 mass% or less, relative to the total amount of the resin layer.

[0025] The matrix material 30 may further contain various conductive agents (conductive carbon, graphite, copper, aluminum, nickel, an iron powder, conductive tin oxide, conductive titanium oxide, an ion conductive agent, and the like), a charging control agent, and the like.

[0026] The particles (for example, the first particles 31 and the second partides 32) may be insulating particles. The particles may be resin particles, or may be inorganic particles. Examples of the material of the resin particles include a urethane resin, a polyamide resin, a fluorine resin, a nylon resin, an acrylic resin, a urea resin, and the like. Examples of the material of the inorganic particles include silica, alumina, and the like. A single type of the materials may be used in some examples, or two or more types thereof may be used in combination in other examples. In order to increase compatibility with respect to the matrix material, dispersion retainability after the particles are added, stability after forming a coating material (pot life), or the like, the particles may be of at least one type selected from the group consisting of nylon resin particles, acrylic resin particles, and polyamide resin particles, or may be of at least one type selected from the group consisting of nylon resin particles and acrylic resin particles.

[0027] The particles may be any suitable particles that are capable of forming an irregularity with respect to the surface of the resin layer in order to sufficiently provide a discharge point. The shape of the particles may be a shape that is capable of forming an irregularity with respect to the surface of the resin layer 3. The shape of the particles may be a spherical shape and an ovoidal shape, an amorphous shape, and/or the like, depending on examples.

[0028] In a case where the particles include the first particles 31 and the second particles 32, a ratio of the content of the first particles 31 to the content of the second particles 32 may be approximately 5 : 1 to 1 : 5 in some examples, or may be approximately 3 : 1 to 1 : 3 in other examples, in order to more easily achieve a suitable charging performance.

[0029] The content of the particles may be approximately 5 mass% to 50 mass%, relative to the total mass of the resin layer 3. The charging performance tends to be more easily satisfied by setting the content of the particles to be approximately 5 mass% or more. The control of particle precipitation at the time of preparing the coating material is further facilitated and coating material stability is better maintained by setting the content of the particles to be approximately 50 mass% or less. For example, the content of the particles may be approximately 10 mass% to 40 mass% or may be approximately 20 mass% to 30 mass%, relative to the total mass of the resin layer 3. In a case where there are a plurality of types of particles as the particles contained in the resin layer 3, the content of the particles described above indicates the total amount of the plurality of types of particles. The content of the particles contained in the resin layer 3, for example, can be quantified by sampling the resin layer 3 from the charging member, and by measuring a weight change (TG), differential heat (DTA), calory (DSC), and the mass (MS) of a volatile component, which occur by heating the sampled resin layer (TG-DTA-MS, DSC (heat analysis)).

[0030] With reference to FIG. 2, in the cross-section of the resin layer 3, a layer thickness A of a portion containing the matrix material 30, without containing the particles in a thickness direction (e.g., a radial direction of the conductive body 5), may be within a range having a minimum of approximately 1.0 pm, of approximately 2.0 pm, or of approximately 3.0 pm, and having a maximum of approximately 7.0 pm, of approximately 6.0 pm, or of approximately 5.0 pm. In a case where the resin layer 3 contains the particles, the layer thickness A corresponds to a thickness of the resin layer 3 at a middle point between the nearest particles. By setting the layer thickness A to be approximately 1.0 pm or more, the resin particles to be added are more easily continuously retained without having any dropout of the resin particles for a long period of time. The layer thickness A may be set to approximately 7.0 urn or less, in order to more easily maintain a suitable charging performance. The layer thickness A may be measured by cutting out a sectional surface of the conductive body 5 with a sharp blade, and by observing the sectional surface with an optical microscope or an electronic microscope.

[0031 ] In a case where the resin layer 3 contains the first particles 31 and the second particles 32, the average of particle diameters (e.g., an average particle diameter B in FIG. 2) of the first particles 31 may be approximately 15.0 pm to 40.0 pm, in order to suppress charging unevenness which may generate an initial image defect. In addition, the average of particle diameters (an average particle diameter C in FIG. 2) of the second particles 32 may be approximately 15.0 pm or more, and may be approximately 40.0 pm or less, in order to suppress the charging unevenness which is the initial image defect. In addition, in order to suppress the charging unevenness, the average particle diameter B of the first particles 31 may be greater than the average particle diameter C of the second particles 32. In some examples, the average particle diameter B of the first particles 31 may be greater than the average particle diameter C of the second particles 32 by approximately 10 pm or more.

[0032] In a case where the resin layer 3 contains the first particles as the particles, the average of the particle diameters of the first particles (the average particle diameter of the first particles) may be approximately 5.0 pm to 50.0 pm, and may be approximately 15.0 pm to 30.0 pm, in order to suppress the charging unevenness which is the initial image defect. [0033] In the present disclosure, the average particle diameter of the particles can be derived by extracting 100 particles randomly, from a population of a plurality of particles with SEM observation, and by obtaining an average value of particle diameters. However, in a case where a particle shape is not a spherical shape, but rather a shape having a variable diameter or non-uniform dimensions, such as an ovoidal shape (having an oval crosssection) or an amorphous shape, an average value of the longest diameter (or longest transverse dimension) and the shortest diameter (or shortest transverse dimension) may be considered as the particle diameter of the particles.

[0034] A ratio (B/A) of the average particle diameter B of the first particles 31 to the layer thickness A of the resin layer 3 may be approximately 5.0 to 30.0. The ratio B/A may be set to approximately 5.0 or more, to more easily increase a charging evenness. The ratio B/A may be set to approximately 30.0 or less, in order to achieve suitable coating properties of a coating liquid for forming a resin layer and to suppress particle dropout. For example, the B/A may be approximately 7.5 to 20.0, or may be approximately 8.0 to 12.5.

[0035] An interparticle distance in the resin layer 3 (namely, an interparticle distance of all of the particles including the first particles 31 and the second particles 32 included in accordance with a case) may be approximately 50 pm to 400 pm. The surface roughness of the resin layer 3 and the particle dropout are more easily suppressed by setting the interparticle distance to be approximately 50 pm or more. The particle dropout is more easily suppressed by setting the interparticle distance to be approximately 400 pm or less. For example, the interparticle distance may be approximately 75 pm to 300 pm, or may be approximately 100 pm to 250 pm. The interparticle distance can be measured on the basis of JIS B0601-1994.

[0036] The resin layer 3 may be formed by impregnating the surface of the originally existing elastic layer with a solution containing an isocyanate compound, and then, by curing the solution. In this case, a cured portion on the surface side of the originally existing elastic layer is the resin layer 3, and other uncured portions are the elastic layer 2. In such a method, the elastic layer may be formed by grinding, and thus, an irregularity may be formed on the surface of the elastic layer such that the resin layer 3 to be formed after solution impregnation forms the irregular surface.

[0037] The isocyanate compound may be 2,6-tolylene diisocyanate (TDI), 4,4'-diphenyl methane diisocyanate (MDI), paraphenylene diisocyanate (PPDI), 1 ,5-naphthalene diisocyanate (NDI), and 3,3-dimethyl diphenyl-4,4'~ diisocyanate (TODI), multimers and modified bodies thereof, and the like.

[0038] A solvent of the solution containing the isocyanate compound may be any suitable solvent that is an organic solvent in which the isocyanate compound can be dissolved. The organic solvent may be ethyl acetate or the like. The solution may further contain carbon black, at least one type of polymer selected from an acrylic fluorine-based polymer and an acrylic silicone-based polymer, a conductivity imparting agent, and the like.

[0039] The resin layer formed by impregnating the elastic layer with the solution containing the isocyanate compound, and then, by curing the solution may contain the elastic body forming the elastic layer 2, and a resin derived from the isocyanate compound. In this case, the elastic body may be formed of a base polymer containing acrylonitrile-butadiene rubber (NBR) or epichlorohydrin rubber as a main component, in order to impart suitable binding properties with respect to the resin derived from the isocyanate compound. The base polymer may contain 50 mass% or more of acrylonitrile-butadiene rubber (NBR) or epichlorohydrin rubber in some examples, or may contain 80 mass% or more of acrylonitrile-butadiene rubber (NBR) or epichlorohydrin rubber in other examples. The resin derived from the isocyanate compound may be a resin having a urea bond, a urethane bond, or the like (a urea resin, a urethane resin, or the like). The resin derived from the isocyanate compound may be bonded to the base polymer and/or the cross-linked body in the elastic body by a urethane bond or the like. [0040] In a case where the resin layer 3 is formed by the above method for impregnating the elastic layer with the solution containing the isocyanate compound, the thickness of the resin layer 3 may be within a range having a minimum of approximately 1.0 pm, of approximately 10.0 urn, or of approximately 20.0 pm, depending on examples, and having a maximum of approximately 250.0 pm, of approximately 200.0 pm, or of approximately 150.0 pm depending on examples.

[0041] Coating Layer

The coating layer 4 contains polysiloxane having a molecular structure having a Si-O-Ti bond and a TiO4/i unit. Here, the "polysiloxane" indicates a compound having a plurality of Si-O-Si bonds (siloxane bonds) in a molecular structure. Three or four O (oxygen) atoms may be bonded to a Si (silicon) atom of the Si-O-Si bond. The polysiloxane may be, for example, a condensate of a monomer component containing hydrolyzable silane or a derivative thereof, and may include a monomer unit derived from a compound having a hydrolyzable silyl group represented by Formula (1 ) described below (hereinafter, referred to as "hydrolyzable silane").

[0042] in Formula (1 ), R³¹ to R³³ each independently indicates a hydrocarbon group. The hydrocarbon group may be, for example, an alkyl group having 1 to 4 carbon atoms.

[0043] The Si-O-Ti bond included in the molecular structure of the polysiloxane, for example, is a bond to be formed between an organic titanium compound and the hydrolyzable silane at the time of polymerizing (condensing) the hydrolyzable silane in the presence of the organic titanium compound such as a titanium oligomer. Namely, it can be said that the polysiloxane having the Si-O-Ti bond in the molecular structure also has a monomer unit derived from the organic titanium compound, in addition to a monomer unit derived from the hydrolyzable silane. The monomer unit derived from the organic titanium compound includes a TiO4/i unit and is included in the polysiloxane as a partial structure having a TiO</i unit. The Si of the Si-O-Ti bond can be the same as the Si of a Si-O-Si bond. Three or four oxygen atoms may be bonded to Si of the Si-O-Ti bond.

[0044] The molecular structure of the polysiloxane described above may include a partial structure in which a plurality of TiO</i units are consecutive. Namely, the polysiloxane may have a Ti-O-Ti bond. A plurality of the partial structures may be included in the molecular structure described above. The polysiloxane having the partial structure can be obtained by using a compound having a TiCU/i unit as a repeating unit (for example, a titanium oligomer), as the organic titanium compound, at the time of polymerizing (condensing) the hydrolyzable silane. For example, a structure represented by Formula (I) described below can be used as the partial structure having the TiCU/i unit.

[0045] In Formula (I), each of the plurality of R^a independently indicates a monovalent hydrocarbon group, w indicates an integer of 2 to 20, and * indicates a bonding hand, w may be 2 to 10, or may be 2 to 6. * is a bonding hand with respect to a constituent unit other than the TIO4/1 unit, for example, a bonding hand with respect to Si. In a case where the molecular structure of the polysiloxane has the following Si-O-Zr bond, * is a bonding hand with respect to Si or Zr.

[0046] The number of carbon atoms of the hydrocarbon group, for example, may be 1 to 12, may be 2 to 8, or may be 3 to 6. A part of the carbon atoms of the hydrocarbon group may be substituted with an oxygen atom or the like. The hydrocarbon group may have a substituent (for example, a substituent forming a chelate structure). The hydrocarbon group may be linear or branched. The hydrocarbon group may be saturated or unsaturated.

[0047] Examples of R^a include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a n-pentyl group, a 2-pentyl group, a 3-pentyl group, a tert-pentyl group, a hexyl group, a heptyl group, an octyl group, and the like. [0048] Examples of the organic titanium compound for forming the partial structure represented by Permute (I) described above include a compound represented by Formula (la) described below.

[0049] R^a and w in Formula (la) correspond to the same as R^a and w, respectively, in Formula (I), and each of the plurality of R^b independently indicates a monovalent hydrocarbon group. Examples of the hydrocarbon group indicated by R^b are the same as those of R^a.

[0050] The content of the monomer unit derived from the organic titanium compound may be within a range having a minimum of approximately 5.0 mol%, of approximately 7.5 mol%, or of approximately 10.0 mol%, relative to the total amount of the monomer units included in the polysiloxane, in order to further suppress the occurrence of a crack without excessively increasing the surface hardness of the coating layer. The content of the monomer unit derived from the organic titanium compound may be within a range having a maximum of approximately 20.0 mol%, of approximately 17.5 mol%, or of approximately 15.0 mol%, relative to the total amount of the monomer units included in the polysiloxane, in order to further increase the surface hardness of the coating layer. For example, the content of the monomer unit derived from the organic titanium compound may be approximately 5.0 mol% to 20.0 mol%, may be approximately 7.5 mol% to 17.5 mol%, or may be approximately 10.0 mol% to 15.0 mol%, relative to the total amount of the monomer units included in the polysiloxane. The content of the monomer unit (the monomer unit having the structure represented by Formula (!) described above) may be set within the example ranges described above when the partial structure represented by Formula (I) described above is set as one monomer unit, so as to further suppress the occurrence of a crack, and to further increase the surface hardness of the coating layer.

[0051 ] The polysiloxane may have a Si-O-Zr bond in the molecular structure described above. The Si-O-Zr bond may be formed between a zirconium chelate compound and the hydrolyzable silane, at the time of polymerizing (condensing) the hydrolyzable silane in the presence of the zirconium chelate compound. Namely, it can be said that the polysiloxane having the Si-O-Zr bond in the molecular structure has a monomer unit derived from the zirconium chelate compound. The Si of the Si-O-Zr bond can be the same as the Si of the Si-O-Si bond. Three or four oxygen atoms may be bonded to the Si of the Si-O-Zr bond.

[0052] The zirconium chelate compound has a zirconium atom (Zr) that is a central metal, and 1 to 4 chelate ligands (polydendate ligands) that are coordinated to the zirconium atom. The zirconium chelate compound accelerates a polymerization (condensation) reaction of the hydrolyzable silane, and contributes to the formation of a coating layer having low surface free energy.

[0053] The chelate ligand may be a bidentate ligand or a tridentate ligand. A ligand atom of the chelate ligand may be an oxygen atom. The chelate ligand may be an acetylacetonate group or an alkyl acetoacetate group. Alkyl of the alkyl acetoacetate group may be alkyl having 1 to 10 carbon atoms. [0054] The zirconium chelate compound may have a monodentate ligand. The monodentate ligand may be an alkoxy group. The number of carbon atoms of the alkoxy group may be 1 to 10.

[0055] The zirconium chelate compound may be zirconium tributoxymonoacetylacetonate, zirconium dibutoxybis(acetylacetonate), zirconium dibutoxybis(ethyl acetoacetate), or the like. Among them, in a case where the zirconium chelate compound is the zirconium dibutoxybis(acetylacetonate), a higher reaction efficiency can be easily obtained at the time of synthesizing the polysiloxane. Accordingly, in a case where the polysiloxane has a monomer unit derived from the zirconium dibutoxybis(acetylacetonate), a higher surface hardness can be more easily obtained, so that the contamination due to the external additive is less likely to occur. A single type of the zirconium chelate compound may be used in some examples, or two or more types thereof may be used in combination in other examples.

[0056] The monomer unit derived from the zirconium chelate compound, for example, is represented by ZrCW The content of the monomer unit derived from the zirconium chelate compound (for example, a ZrCU/2 unit) may be adjusted to achieve a suitable reaction time, a suitable condensation rate, or the like. The reaction time tends to decrease as the used amount of the zirconium chelate compound increases, and the condensation rate tends to increase as the used amount of the zirconium chelate compound decreases. The content of the monomer unit derived from the zirconium chelate compound may be within a range having a minimum of approximately 2.0 mol%, of approximately 3.0 mol%, or of approximately 4.0 mol%, and having a maximum of 10.0 mol%, of 8.0 mol%, or of 6.0 mol%, relative to the total amount of the monomer units included in the polysiloxane. [0057] The monomer unit derived from the hydrolyzable silane contained in the poiysiloxane may be a monomer unit derived from hydrolyzable silane having a cross-linkable group. Here, the cross-linkable group is a group for forming a cross-linked structure by reacting with the other cross-linkable group, in the presence of cations or the like, and for example, is a cationic polymerizable group such as an epoxy group. Namely, the example hydrolyzable silane having the cross-linkable group is hydrolyzable silane having a cationic polymerizable group (an epoxy group or the like).

[0058] The poiysiloxane may have a cross-linked structure to be formed by a reaction between the cross-linkable groups described above. Namely, the poiysiloxane may be a cross-linked body of the poiysiloxane having the cross- linkable group (cross-linkable poiysiloxane). The cross-linked structure described above may be referred to as a cross-linked structure derived from the cross-linkable group. The cross-linked structure described above, for example, is a cross-linked structure derived from an epoxy group. The cross-linkable poiysiloxane will be described below.

[0059] The hydrolyzable silane having the cross-linkable group may be monofunctional hydrolyzable silane or difunctional or higher hydrolyzable silane. Namely, there may be one cross-linkable group, or there may be a plurality of cross-linkable groups. The equivalent of the cross-linkable group (the molecular weight per 1 mol of the cross-linkable group) of the hydrolyzable silane having the cross-linkable group, for example, is approximately 100.0 g/mol to 300.0 g/mol.

[0060] The hydrolyzable silane having the cross-linkable group may be a compound represented by Formula (2) or Formula (3) described below, in order to suppress the occurrence of polymerization inhibition due to oxygen at the time of forming the polysiloxane and to easily obtain the coating layer exceilent in the surface hardness by improving surface curing properties.

[0061 ] In Formula (2), R¹ to R³ each independently indicates a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a carboxy group, or an amino group, X indicates a single bond or a divalent organic group, and Q indicates a hydrolyzable silyl group (-Si(OR³'ⁱ)(OR³²)(OR³³)) represented by Formula (1 ) described above.

[0062] In Formula (3), R⁴ to R⁵ each independently indicates a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, a carboxy group, or an amino group, R⁶ to R⁷ each independently indicates a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, m indicates an integer of 4 to 12, and Q indicates a hydrolyzable silyl group (~Si(OR³¹)(OR³²)(OR³³)) represented by Formula (1 ) described above.

[0063] The divalent organic group of X may be a divalent hydrocarbon group having 1 to 16 carbon atoms. A part of the carbon atoms of the hydrocarbon group may be substituted with an oxygen atom. The hydrocarbon group may be linear or branched, and may be saturated or unsaturated. The divalent organic group may be a group represented by Formula (4) or Formula (5) described below.

[0064] In Formula (4), R⁸ to R⁹ each independently indicates a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and I indicates an integer of 1 to 8. In Formula (5), Rⁱ⁰ to R¹³ each independently indicates a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and p and q each independently indicates an integer of 1 to 8. In Formula (4) and Formula (5), * indicates a bonding hand with respect to Q.

[0065] In some examples, the hydrolyzable silane having the cross-linkable group may be (3-glycidoxypropyl) trimethoxysilane, (3-glycidoxypropyl) triethoxysilane, 2-(3,4-epoxy cyclohexyl) ethyl trimethoxysilane, 2-(3,4-epoxy cyclohexyl) ethyl triethoxysilane, or the like. A single type of the hydrolyzable silane having the cross-linkable group may be used in some examples, or two or more types thereof may be used in combination in other examples.

[0066] In a case where the hydrolyzable silane having the cross-linkable group is the compound represented by Formula (2) described above, the monomer unit derived from the hydrolyzable silane having the cross-linkable group can be represented by Formula (6) described below.

[006/] R¹ to R³ and X in Formula (6) correspond to the same as R¹ to R³ and

X, respectively, in Formula (2), and n indicates 0 or 1 .

[0068] The monomer unit having the structure represented by Formula (6) described above may be a monomer unit having a structure represented by

Formula (7) or Formula (8) described below.

[0069] n in Formula (7) and Formula (8) is the same as n in Formula (6). I in Formula (7) is the same as I in Formula (4), and p and q in Formula (8) are the same as p and q in Formula (5).

[0070] In a case where the hydrolyzable silane having the cross-linkable group is the compound represented by Formula (3) described above, the monomer unit derived from the hydrolyzable silane having the cross-linkable group has a structure represented by Formula (9) described below. [0071 ] R⁴ to R⁷, m, and X in Formula (9) correspond to the same as R⁴ to R⁷, m, and X, respectively, in Formula (3).

[0072] The monomer unit having the structure represented by Formula (9) described above may be a monomer unit having a structure represented by Formula (10) or Formula (11 ) described below.

[0073] I in Formula (10) is the same as I in Formula (4), and p and q in Formula (11 ) are the same as p and q in Formula (5).

[0074] The content of the monomer unit derived from the hydrolyzable silane having the cross-linkable group may be approximately 60.0 mol% or more, may be approximately 64.0 mol% or more, or may be approximately 74.0 mol% or more, relative to the total amount of the monomer units included in the polysiloxane, in order to achieve a more suitable surface hardness of the coating layer. The content of the monomer unit derived from the hydrolyzable silane having the cross-linkable group may be approximately 95.0 mol% or less, may be approximately 93.0 mol% or less, or may be approximately 90.0 mol% or less, relative to the total amount of the monomer units included in the polysiloxane, in order to suppress the formation of a crack without excessively increasing the surface hardness of the coating layer. For example, the content of the monomer unit derived from the hydrolyzable silane having the cross-linkable group may be approximately 60.0 mol% to 95.0 mol%, may be approximately 64.0 mol% to 93.0 mol%, or may be approximately 74.0 mol% to 90.0 mol%, relative to the total amount of the monomer units included in the polysiloxane. The content of a monomer unit derived from hydrolyzable silane having an epoxy group may be set within the example ranges described above, in order to further suppress the formation of a crack, and to further increase the surface hardness of the coating layer.

[0075] The polysiloxane may further have monomer units other than the monomer units described above. For example, the polysiloxane may further have a monomer unit derived from hydrolyzable silane not having the crosslinkable group.

[0076] The content of the polysiloxane may be 90 mass% or more, may be 95 mass% or more, or may be 98 mass% or more, relative to the total mass of the coating layer.

[0077] The coating layer containing the polysiloxane described above may be a layer containing a cured product of a curable composition containing the cross-linkable polysiloxane. In such a case, the coating layer contains the cross-linked body of the cross-linkable polysiloxane (a body having a bond (a cross-linkage) to be formed by the reaction between the cross-linkable groups).

[0078] The cross-linkable polysiloxane is the polysiloxane having the crosslinkable group, and may be for example, a condensate of a monomer component containing the hydrolyzable silane having the cross-linkable group, the organic titanium compound, and in some examples, the zirconium chelate compound. Therefore, the cross-linkable polysiloxane is capable of having the monomer unit derived from the hydrolyzable silane having the crosslinkable group, the monomer unit derived from the organic titanium compound, and in some examples, the monomer unit derived from the zirconium chelate compound.

[0079] In a case where the cross-linkable polysiloxane has a cationic polymerizable group (an epoxy group or the like) as the cross-linkable group, the curable composition contains the cross-linkable polysiloxane and an acid generating agent.

[0080] The acid generating agent may be a photo-acid generating agent, or may be a thermal-acid generating agent. A single type of the acid generating agent may be used in some examples, or two or more types thereof may be used in combination in other examples.

[0081 ] The photo-acid generating agent may be a photo-acid generating agent that can be activated with light having a wavelength of 365 nm to 405 nm from a UV-LED light source, in order to suppress damage to a base due to heat from a light source and oxidation degradation of the coating layer. The photo-acid generating agent may be a triarylsulfonium salt-based photoacid generating agent or the like.

[0082] The thermal-acid generating agent may be a thermal-acid generating agent that can be activated at a low temperature (for example, 250°C or less), in order to suppress the damage to the base due to heat and the oxidation degradation of the coating layer. The thermal-acid generating agent may be an aromatic sulfonium salt-based thermal-acid generating agent, an aromatic iodonium salt-based thermal-acid generating agent, or the like. A counter anion of such a thermal-acid generating agent may be a hexafluorophosphoric acid, a tritrifluoromethane sulfonic acid, a perfluorobutane sulfonic acid, or the like.

[0083] The content of the acid generating agent may be adjusted in order to achieve a suitable reaction time or the like. The content of the acid generating agent may be 1.0 parts by mass or more, may be 3.0 parts by mass ar more, ar may be 5.0 parts by mass or more, and may be 10.0 parts by mass or less, may be 8.0 parts by mass ar less, or may be 7.0 parts by mass or less, with respect to 100 parts by mass of the total amount of a cationic polymerizable compound, the organic titanium compound, and the zirconia chelate compound (for example, the total amount of a compound having an epoxy group, the organic titanium compound, and the zirconia chelate compound).

[0084] The coating layer may further contain components other than the components derived from the curable composition (a liquid medium or the like derived from the coating liquid). In the coating layer, the content of the components other than the components derived from the curable composition may be 5 mass% or less, may be 1 mass% or less, or may be 0.5 mass% or less, relative to the total mass of the coating layer.

[0085] A thickness D (a "D" portion in FIG. 2) of the coating layer 4 may be approximately 50 nm or more, or may be approximately 70 nm or more, and may be approximately 500 nm or less, may be approximately 400 nm or less, or may be approximately 300 nm or less. Therefore, the thickness D of the coating layer 4 may be approximately 50 nm to 500 nm. The layer thickness D of the coating layer 4 may be increased, so as to increase the stress resistance of the coating layer 4, and thereby further suppress the occurrence of a crack formation.

[0086] The surface of the coating layer 4, namely, an outermost surface S of the conductive body 5 may have an irregularity to be formed by the resin layer 3.

[0087] An average interval (Sm) of the irregularities of the outermost surface S of the conductive body 5 may be approximately 50 pm to 400 pm, may be approximately 75 pm or more, or may be approximately 100 pm or more, and may be approximately 300 pm or less, or may be approximately 250 um or less, in order to obtain a better image quality.

[0088] Ten-point average roughness (Rzjis) of the outermost surface S of the conductive body 5 may be 11.5 pm or more, may be 15.0 pm or more, may be 18.0 pm or more, may be 20.0 pm or more, may be 22.0 pm or more, may be 22.5 pm or more, or may be 23.0 pm or more, in order to suppress the charging unevenness. The ten-point average roughness (Rzjis) of the outermost surface of the conductive body 5 may be 32.0 pm or less, may be 30.0 pm or less, may be 29.0 pm or less, may be 28.0 pm or less, may be 27.5 pm or less, may be 27.0 pm or less, may be 26.5 pm or less, or may be 26.0 pm or less, in order to suppress rotation unevenness (a circumferential speed deviation) of the charging roller 10.

[0089] The average interval (Sm) of the irregularities and the ten-point average roughness (Rzjis) are measured on the basis of JIS B0601 -2001 by using a surface roughness meter SE-3400 manufactured by Kosaka Laboratory Ltd. The average interval (Sm) of the irregularities and the ten- point average roughness (Rzjis), and other surface properties of the conductive body can be adjusted by changing the size, the shape, the amount, and the interparticle distance of the particles to be contained in the resin layer 3, the layer thickness of the coating layer 4, and the like.

[0090] The conductive body 5 may include a surface that is curved with respect to the rotation axis line L. Namely, the surface of the coating layer 4 may be curved with respect to the rotation axis line L. The radial distance (corresponding to 1/2 of an outer diameter) of the conductive body 5, which is the shortest distance from the rotation axis line L to the surface of the conductive body 5 (the surface of the coating layer 4) varies along the direction of the rotation axis iine L (a longitudinal direction). The radiai distance is the greatest (maximum) at a center point of the conductive body 5 on the rotation axis line L (a center point of the conductive body 5 in the longitudinal direction), and decreases toward each of the opposite end portions of the conductive body 5.

[0091 ] A crown amount can be used as an index expressing a roller shape of the conductive body 5. The crown amount of the conductive body 5 is defined as follows:

Crown Amount ~ d2 - (d1 + d3)/2

In the above expression, d1 indicates the outer diameter of the conductive body 5 in a position that is 30 mm separated from a first end of the conductive body 5 in the longitudinal direction (a rubber length) toward the center point, d2 indicates the outer diameter of the conductive body 5 at the center point of the conductive body 5 in the longitudinal direction (the rubber length), and d3 indicates the outer diameter of the conductive body 5 in a position that is offset from the second end of the conductive body 5 by 30 mm, in the longitudinal direction (the rubber length) toward the center point.

[0092] The crown amount of the conductive body 5 may be 50 pm or more, may be 60 urn or more, or may be 70 urn or more, and may be 130 pm or less, may be 120 pm or less, or may be 110 pm or less, to achieve a stable charging evenness for a long period of time while allowing the charging roller 10 to suitably cohere to the photoreceptor, and of maintaining the granularity of image quality.

[0093] The charging member described above may be provided in an example image forming apparatus, as charging device to charge the photoreceptor. For example, the charging member may perform a charging treatment with respect to the surface of the photoreceptor that is an image carrier. Accordingly, the example image forming apparatus includes the photoreceptor, and the charging member to charge the photoreceptor.

[0094] In the example image forming apparatus, a direct-current voltage may be applied to the charging member. In such a case, a bias voltage to be applied while an image is output may be -1000 V to -1500 V.

[0095] Manufacturing Method of Charging Member

Hereinafter, an example method of manufacturing a charging member will be described based on a manufacturing method of the example charging roller 10.

[0096] The manufacturing method of the charging roller 10 includes preparing the conductive base 6 that is mountable on the conductive support 1 , preparing a coating liquid containing a curable composition, spraying the coating liquid onto the surface of the conductive base 6, and curing the curable composition to form the coating layer 4 on the conductive base 6.

[0097] The conductive base 6, for example, can be prepared as follows. Namely, first, a material for forming an elastic layer and a coating liquid for forming a resin layer are prepared. The material for forming an elastic layer can be prepared by kneading a material for the elastic layer 2 with a kneading machine such as a kneader. In addition, the coating liquid for forming a resin layer can be prepared by kneading a material for the resin layer 3 with a kneading machine such as a roller, by adding an organic solvent to the mixture, and by performing mixing and stirring. Next, a metal mold for injection molding in which a core bar that is the conductive support 1 is set is filled with the material for forming an elastic layer, and is thermally crosslinked in a predetermined condition. Subsequently, demolding is performed, and thus, a base roil is manufactured in which the eiastic layer is formed along the outer circumferential surface of the conductive support 1 . Next, the coating liquid for forming a resin layer is applied onto an outer circumferential surface of the base roll described above, so as to form the resin layer 3. As described above, it is possible to prepare the conductive base 6 including the elastic layer 2 formed on the outer circumferential surface of the conductive support 1 , and the resin layer 3 formed on the outer circumferential surface of the elastic layer 2.

[0098] In addition to an injection molding method, the formation method of the elastic layer may include a cast molding method, or a method in which press molding and grinding are combined together. In addition, a coating method of the coating liquid for forming a resin layer may correspond to any suitable method such as a dipping method, a roll coating method, and the like. [0099] The coating liquid, for example, contains the curable composition, and a liquid medium (a solvent or a dispersion medium) in which the components of the composition are dissolved or dispersed. The curable composition may contain, for example, the cross-linkable polysiloxane, the organic titanium compound, and in some examples, the zirconium chelate compound and the acid generating agent.

[0100] The liquid medium may contain water. The liquid medium may further contain an alcohol solvent. Namely, the liquid medium may be a mixed liquid of water and the alcohol solvent. In this case, the content of water in the liquid medium may be 10.0 mass% or more, and may be 60.0 mass% or less, relative to the total mass of the liquid medium. Methanol, ethanol, isopropyl alcohol, or the like may be used as the alcohol solvent.

[0101 ] The content of the liquid medium may be adjusted in order to achieve a suitable viscosity of the coating liquid. The content of the liquid medium may be 95.0 mass% to 99.9 mass%, relative to the total mass of the coating liquid.

[0102] The coating liquid described above can be obtained by mixing each of the components to be contained in the curable composition and the liquid medium. In a case of using the hydrolyzable silane having the cationic polymerizable group (an epoxy group or the like), for example, first, monomer components including the hydrolyzable silane having the cationic polymerizable group (the epoxy group or the like), the organic titanium compound, and in some examples, the zirconium chelate compound, are heated to reflux in the presence of a solvent, and cross-linkable polysiloxane having a cationic polymerizable group is obtained as a reaction (polymerization) product. Here, the monomer components indicate components to be incorporated in the structure of the polysiloxane that is generated after the reaction. The solvent may be water, may be alcohol such as ethanol, or may be a mixture thereof, or the like. Next, the obtained reaction product, the acid generating agent, and the liquid medium are mixed to obtain the coating liquid. In such a case, the reaction product and the acid generating agent may be mixed by being dissolved in advance in the liquid medium.

[0103] The amount of the monomer components and the acid generating agent to be used for manufacturing the coating liquid described above may be adjusted such that the content of the monomer unit derived from each of the components is within the example ranges described above. The amount of the hydrolyzable silane having the epoxy group may be approximately 60.0 mol% to 95.0 mol%, relative to the total amount of the monomer components. The amount of the organic titanium compound may be approximately 5.0 mol% to 20.0 mol%, relative to the total amount of the monomer components. The amount of the zirconium chelate compound may be approximately 2.0 mol% to 10.0 mol%, relative to the total amount of the monomer components. [0104] An application method of the coating liquid may include a suitable method such as a dipping method, a spray coating method, a roll coating method, and/or the like.

[0105] Drying or the like may be performed after the coating liquid is applied and before the curable composition is cured so that the solvent in the formed coating may be removed. The drying may be performed at 130°C to 220°C. [0106] A curing method of the curable composition is not particularly limited. In a case where the curable composition contains the acid generating agent, any suitable curing process (heating, light irradiation, or the like) may be adopted, in accordance with the type of acid generating agent. The heating and the light irradiation may be used together in the curing process. In a case of using the photo-acid generating agent, the curable composition may be cured by being irradiated with light having a wavelength of 365 nm to 405 nm from the UV-LED light source, in order to suppress the damage on the base due to heat generated from the light source and the oxidation degradation of the coating layer. The UV-LED light source may be a UV- LED light source manufactured by Hamamatsu Photonics K.K., a UV-LED light source manufactured by HOYA Corporation, a UV-LED light source manufactured by Iwasaki Electric Co., Ltd., a UV-LED light source manufactured by Ushio Inc., a UV-LED light source manufactured by Heraeus K.K., a UV-LED light source manufactured by AITEC SYSTEM Co., Ltd., a UV-LED light source manufactured by Micro-Sphere S.A., and the like. In addition, in a case of using the thermal-acid generating agent, the curable composition may be cured by heating to 250°C or less, in order to suppress the damage to the base due to heat and the oxidation degradation of the coating layer.

Test Examples

[0107] Hereinafter, Test Examples of the charging member will be described, and it is understood that the charging member is not limited to these Test Examples.

[0108] Test Examples 1 to 21

Preparation of Material for Forming Elastic Layer

A material for forming an elastic layer was prepared by compounding together and subsequently kneading with a roller, 100.00 parts by mass of epichlorohydrin rubber ("EPICHLOMER CG-102", manufactured by DAISO CHEMICAL CO., LTD.) as a rubber component, 5.00 parts by mass of sorbitan fatty acid ester ("SPLENDER R-300", manufactured by Kao Corporation) as a lubricant, 5.00 parts by mass of a ricinoleic acid as a softener, 0.50 part by mass of a hydrotalcites compound ("DHT-4A", manufactured by Kyowa Chemical Industry Co., Ltd.) as an acid acceptor, 1.00 part by mass of tetrabutyl ammonium chloride ("tetrabutyl ammonium chloride", manufactured by Tokyo Chemical Industry Co., Ltd.) as a conductive agent (an ion conductive agent), 50.00 parts by mass of silica ("Nipsil ER", manufactured by Tosoh Silica Corporation) as a filler, 5.00 parts by mass of zinc oxide as a cross-linking promoter, 1.50 parts by mass of dibenzothiazole sulfide, 0.50 part by mass of tetramethyl thiuram monosulfide, and 1.05 parts by mass of sulfur as a cross-linking agent. Consequently, the material for forming an elastic layer was obtained. [0109] Preparation of Coating Liquid for Forming Resin Layer

A mixed liquid was prepared by mixing into tetrahydrofuran (THF), 100.00 parts by mass of thermoplastic N-methoxy methylated 6-nylon ("Toresin F-30K”, manufactured by Nagase ChemteX Corporation) as a polymer component, 5.00 parts by mass of methylene bisethyl methyl aniline ("CUREHARD-MED", manufactured by lhara Chemical Industry Co., Ltd.) as a curing agent, and 18.00 parts by mass of carbon black ("Denka Black HS100", manufactured by Denka Company Limited) as a conductive agent (an electronic conductive agent). In the mixed liquid, two types of amorphous nylon resin particles having different average particle diameters (25.0 u.m and 5.0 pm) ("Orgasol Series”, manufactured by Arkema S.A.) were added as the first particles 31 and the second particles 32, and were sufficiently stirred until the solution became uniform. An additive amount was adjusted based on the total amount of the resin layer 3 to be obtained such that the content of the first particles 31 was 25 mass% and the content of the second particles 32 was 5 mass%. Subsequently, each component in the solution was dispersed by using a double roll. Accordingly, a coating liquid for forming a resin layer was obtained.

[0110] The average particle diameter of the first particles 31 and the second particles 32 was measured as follows. Namely, 100 particles were extracted randomly from a population of a plurality of particles with SEM observation, and an average value of particle diameters was set to the average particle diameter of the resin particles. A particle shape of the used resin particles was an amorphous shape, and thus, an average value of the longest diameter (longest transverse dimension) and the shortest diameter (shortest transverse dimension) of the observed particles was set as the particle diameter of the respective particles.

[0111] Preparation of Conductive Base

A roll molding metal mold including a cylindrical roll molding space was prepared, and a core bar having a diameter of 8 mm (the conductive support 1 ) onto which a conductive adhesive agent was applied was set to be coaxial with the roll molding space. The material for forming an elastic layer prepared as described above, was injected into the roll molding space in which the core bar was set, was subsequently heated at 170°C for 30 minutes, and then, was cooled, and was further demolded. Accordingly, a base roll including the conductive support 1 as a conductive axis body, and the elastic layer 2 having a thickness of 2 mm (a thickness in the central position in the rotation axis line L direction) that was formed along the outer circumferential surface of the conductive support 1 was obtained.

[0112] Next, the coating liquid for forming a resin layer prepared as described above, was applied onto the surface of the elastic layer 2 of the base roll by a roll coating method. At this time, the coating was performed while an excess coating liquid was scraped with a scraper to achieve a suitable film thickness. After a coated film was formed, the film was heated at 150°C for 30 minutes so as to form the resin layer 3 having a layer thickness A of 5.0 pm. Accordingly, a conductive base including the elastic layer 2 formed along the outer circumferential surface of the axis body (the conductive support 1 ), and the resin layer 3 formed along the outer circumferential surface of the elastic layer 2 was obtained.

[0113] According to the above preparation, a roller including the axis body (the conductive support 1 ) and the conductive base (the elastic layer 2 and the resin layer 3) was obtained. [0114] Preparation of Coating Liquid

First, hydrolyzable silane having an epoxy group (Ep silane), an organic titanium compound (an organic Ti compound), and a zirconium chelate compound (a Zr chelate compound) as monomer components, and water and ethanol as a liquid medium were mixed according to the respective combinations shown in Tables 1 to 3, and then, were stirred at a room temperature. Next, the mixture was heated to reflux for 24 hours, and thus, a reaction product containing a condensate of the hydrolyzable silane was obtained. The condensate is polysiloxane having a molecular structure having a Si-O-Ti bond, a Si-O-Zr bond, a T1O4/1 unit, and a ZrO4/2 unit. The obtained reaction product was added to a mixed solvent of 2-butanol and ethanol, so as to obtain a condensate-containing alcohol solution having a solid content shown in Tables 1 to 3. In this case, monomer components (the hydrolyzable silane having the epoxy group, the organic titanium compound, and the zirconium chelate compound) were compounded at a compounding ratio shown in Tables 1 to 3 such that the total amount was 100 mol%. In addition, a compounding amount of water was adjusted such that ROR was a value shown in Tables 1 to 3. Here, ROR indicates a molar number ratio of water with respect to a condensation point of the hydrolyzable silane to be used. For example, the minimum number of water molecules for condensing one molecule of hydrolyzable silane having a trimethoxy group is 3. Such a relationship is set to ROR = 1 .0. In some examples, the ROR may be set within a range of 1 .0 < ROR < 2.0.

[0115] Next, an acid generating agent shown in Tables 1 to 3 was added to the condensate-containing alcohol solution. In such a case, an additive amount of the acid generating agent was 5 parts by mass with respect to 100 parts by mass of the solid content in the condensate-containing alcohol solution. Accordingly, respective coating liquids of Test Examples 1 to 21 were obtained.

[0116] Manufacturing of Charging Roller 10

The prepared coating liquid was applied onto the surface of a conductive base of a roller prepared as described above by a roll coating method, so as to form a coated film. After the coated film was formed, in a case where a thermal-acid generating agent was used as the acid generating agent, the coated film was cured by being heated in a condition shown in Table 2 or 3, and in a case of using a photo-acid generating agent as the acid generating agent, the coated film was cured by being irradiated with light in a condition shown in Tables 1 to 3 by using a UV irradiation device (manufactured by Heraeus K.K.) including a UV-LED light source. Accordingly, the coating layer 4 having a layer thickness shown in Tables 1 to 3 was formed. In Tables 1 to 3, a wavelength of 365/405 nm indicates using a UV-LED having a wavelength peak at 365 nm and at 405 nm.

[0117] According to the above-described manufacturing method, the charging roller 10 including the axis body (the conductive support 1 ), and the conductive body 5 including the elastic layer 2 formed along the outer circumferential surface of the axis body, the resin layer 3 formed along the outer circumferential surface of the elastic layer 2, and the coating layer 4 formed along the outer circumferential surface of the resin layer 3 was prepared.

[0118] Comparative Test 1

A charging roller was prepared similarly as in Test Examples 1 to 21 , with the exception that the organic titanium compound was not used. The combination and the compounding ratio of the components used for preparing the coating liquid, the solid content of the condensate-containing alcohol solution, the compounding amount (ROR) of water, the curing process, and the layer thickness of the coating layer were as shown in Table 2.

[0119] Evaluation

Measurement of Microhardness

Martens hardness (HM) and elastic deformation power (r|IT) of the coating layer at 25°C were measured on the basis of ISO 14577, by using a microhardness tester (Product Name: FISCHERSCOPE HM2000 (FISCHERSCOPE: Registered Trademark)) manufactured by FISCHER INSTRUMENTS K.K. An indentation depth was 1/10 of a film thickness not to be affected by the base. Results are shown in Tables 1 to 3.

[0120] Endurance Test

The charging member (the charging roller) obtained as described above was installed in Multixpress C8640 ND manufactured by Samsung Electronics Co., Ltd., to obtain an image forming apparatus, and an endurance test (the formation of an image) was performed in accordance with the following image forming conditions:

• Printing Environment: in Low Temperature Low Humidity Environment (15°C/10%RH)

■ Printing Condition: General Printing Speed of 305 mm/sec and Half Speed thereof, Number of Printed Sheets (80 kPV), Type of Sheet (Office Paper EC)

• Load with respect to Conductive Support End Portion: 5.88 N on

One Side

■ Applied Bias: Set so that Photoreceptor Surface Potential reaches - 600 V

[0121 ] Evaluation of Crack Resistance

A surface state of the charging roller after the endurance test described above (after 500 kcycles) was visually checked to evaluate crack resistance. The crack resistance was evaluated based on the following standards. Results are shown in Tables 1 to 3.

A: No occurrence of any crack is identified.

B: The occurrence of slight cracks is identified in the vicinity of fine particles, but the number and size of the cracks do not affect the image.

C: The occurrence of a plurality of cracks is identified in the vicinity of fine particles, but the number and size of the cracks do not affect the image.

D: The occurrence of a plurality of cracks is identified in the vicinity of fine particles, and the number and size of the cracks affect the image.

[0122] Evaluation of Surface Contamination

Surface contamination of the charging roller after the endurance test described above (after 500 kcycles) was evaluated. The surface contamination of the charging roller was mainly derived from silica of an external additive to be used in a toner, and thus, was evaluated by quantifying an element Si on the surface of the charging roller with a fluorescence X-ray measurement device (EDXL300: manufactured by Rigaku Corporation). Namely, in a chamber of the fluorescence X-ray measurement device, the charging roller was arranged such that the center of the charging roller was aligned with a detector, and the element Si on the surface of the charging roller was quantified. Such measurement was performed with respect to the charging roller before the image was formed and after the image was formed (for each 20 kPV), to calculate a difference ASi [cps/mA] in the amount of Si (= Amount of Si [cps/mA] after Endurance Test - Amount of Si [cps/mA] before Endurance Test). Next, the difference ASi was plotted on a vertical axis, the total number of rotations of the photoreceptor was plotted on a horizontal axis, and the surface contamination was evaluated based on the following standards, by using the slope of the obtained graph as an index.

Evaluation A: ASi < 1000 [cps/mA]

Evaluation B: 1000 [cps/mA] < ASi < 2000 [cps/mA]

Evaluation C: 2000 [cps/mA] < ASi < 3000 [cps/mA]

Evaluation D: 3000 [cps/mA] < ASi The A Si compared to the number of rotations of the photoreceptor decreases with a decrease of the slope of the obtained graph, so that the contamination due to the external additive is less likely to occur. Results are shown in Tables 1 to 3.

HP Record ID 8 0123] [Table 1]

Ep Organic Ti Zr chelate Measurement of

Curing silane compound compound microhardness

Acid Solid UV-LED Layer

Crack Surface

KBM- gene thickness

PC-200 ZC-580 ROR rating content

Cumulative HM niT resistance contaminatio 303 agent [wt%] Wavelength

[mol%] [mol%] light amount [N/mm [mol%] ²]

[nm] [%] [mJ/cm²]

Test

92.9 5.0 2.1 1.0 CPI-310S 0.5 365 5000 50 198 24.0 C C

Example 1

Test

87.9 10.0 2.1 1.0 CPI-310S 0.5 365 5000 50 187 35.0 B B Example 2

Test

82.9 15.0 2.1 1.0 CPI-410S 0.5 365/405 5000 50 179 32.0 B B Example 3

Test

80.4 17.5 2.1 1.0 CPI-410S 0.5 365/405 5000 50 170 35.0 B B Example 4

Test

77.9 20.0 2.1 1.0 CPI-410S 0.5 365/405 5000 50 162 37.0 B C Example 5

HP Record ID 8 0124] [Table 2]

Zr

Organic Curing Measurement

Ep chelate Ti comLayer of silane com| Acid pound Solid UV-LED Thermal curing ound „ | thick- microhardness p genera- content Surface

^OR | ting ness Crack

KBM- [wt%] WaveCumulative contami¬

PC-200 AKZ947 | agent Temperature Time [pm] HM _nIT resistance 403 length light amount nation

[mol%] [mol%] [°C] [min] [N/mm²] [%] [mol%] [nm] [mJ/cm²]

Test

86.5 7.5 6.0 1.5 SI-B3 1.0 130 20 100 178 30.0 A B

Example 6

Test

76.5 17.5 6.0 1.5 SI-B3 1.0 130 20 100 162 38.0 B B

Example 7

Test

84.0 10.0 6.0 1.5 SI-B5 1.5 - - 160 20 150 174 35.0 A A

Example 8

Test

79.0 15.0 6.0 1.5 SI-B5 1.5 160 20 150 167 37.0 A A

Example 9

Test

89.0 5.0 6.0 1 5 I ^CPI” 2.5 365 9000 - 250 183 24.0 B B

Example 10 i 310S

Test

86.5 7.5 6.0 1.5 SI-B3 2.5 - - 130 20 250 178 30.0 A B

Example 11

Test

76.5 17.5 6.0 1.5 SI-B3 2.5 130 20 250 162 38.0 B B

Example 12

Test . . I CPI- 365/

74.0 20.0 6.0 1.5 I 2.5 9000 250 151 40.0 B C

Example 13 I 410S 405

Test

84.0 10.0 6.0 1.5 SI-B5 3.0 160 20 300 174 35.0 A A

Example 14

Test

79.0 15.0 6.0 1.5 SI-B5 3.0 - - 160 20 300 167 37.0 A A

Example 15 omparative _{1 9} i CPI-

94.0 0 6.0 0.5 365 5000 - - 50 200 5.0 D D

Test 1 \ 310S

HP Record ID 8 0125] [Table 3]

Zr

Organic Measurement

Ep chelate Ti comCuring of silane comAcid Layer pound Solid microhardness Surface pound generathick- Crack

ROR content contami- ting UV-LED Thermal curing ness resistance

KBM- PC- ZC- [wt%] nation agent Wave- 1 Cumulative [urn] HM r;IT 303 200 540 Temperature Time length | light amount [N/mm²] [%] [mol%] [mol%] [mol%] [°C] [min] [nm] i [mJ/cm²]

Test

89.5 7.5 3.0 1.2 SI-B3 4.0 I 130 20 400 178 30.0 B B

Example 16

Test

79.5 17.5 3.0 1.2 SI-B3 4.0 I 130 20 400 162 38.0 B B

Example 17

Test CPI-

92.0 5.0 3.0 1.2 5.0 365 15000 - 500 198 24.0 C

Example 18 3108 c

Test CPI-

87.0 10.0 3.0 1.2 5.0 365 15000 500 187 35.0 B B

Example 19 3108

Test CPI- 365/ I

82.0 15.0 3.0 1.2 5.0 405 | 15000 - - 500 179 32.0 B B

Example 20 4108

Test CPI-

77.0 20.0 3.0 1.2 5.0 i 15000 500 162 37.0 B C

Example 21 4108 405 i

[0126] The compounds shown in Tables 1 to 3 are defined as follows:

• KBM-303: Product Name, manufactured by Shin-Etsu Chemical Co., Ltd., 2-(3,4-Epoxy Cyclohexyl) Ethyl Trimethoxysilane

. KBM-403: Product Name, manufactured by Shin-Etsu Chemical Co., Ltd., (3-Glycidoxypropyl) Trimethoxysilane

• PC-200: Product Name, manufactured by Matsumoto Fine Chemical Co., Ltd., Titanium Oligomer (Compound Represented by Formula (la) Described above)

• ZC-580: Product Name, manufactured by Matsumoto Fine Chemical Co., Ltd., Solution of Zirconium Dibutoxybis(Ethyl Acetoacetate) (Solid Content of 70 mass%)

• AKZ947: Product Name, manufactured by Gelest, Inc., Solution of Zirconium Dibutoxybis(Acetylacetonate) (Solid Content of 25 mass%)

. Z. C-540: Product Name, manufactured by Matsumoto Fine Chemical Co., Ltd., Solution of Zirconium Tributoxymonoacetylacetonate (Solid Content of 70 mass%)

• CPI-31 OS: Product Name, manufactured by San-Apro Ltd., Triarylsulfonium Salt-Based Photo-Acid Generating Agent

• CPI-41 OS: Product Name, manufactured by San-Apro Ltd., Triarylsulfonium Salt-Based Photo-Acid Generating Agent

. SI-B3: Product Name, manufactured by SANSHIN CHEMICAL INDUSTRY CO., LTD., Aromatic Sulfonium Salt-Based Thermal-Acid Generating Agent

• SI-B5: Product Name, manufactured by SANSHIN CHEMICAL INDUSTRY CO., LTD., Aromatic Sulfonium Salt-Based Thermal-Acid Generating Agent [0127] it is to be understood that not ail aspects, advantages and features described herein may necessarily be achieved by, or included in, any one particular example. Indeed, having described and illustrated various examples herein, it should be apparent that other examples may be modified in arrangement and detail is omitted.

Claims

1 . A charging member comprising: a conductive support; and a conductive body mounted on the conductive support, wherein the conductive body comprises: an elastic layer located on the conductive support; a resin layer located on the elastic layer; and a coating layer located on the resin layer, wherein the coating layer comprises polysiloxane having a molecular structure comprising a Si-O-Ti bond and a TiCU/i unit.

2. The charging member according to claim 1 , wherein the molecular structure of the polysiloxane comprises a partial structure comprising the TIO4/1 unit, wherein the partial structure is defined according to a Formula (I) represented by:

wherein each R^a independently indicates a monovalent hydrocarbon group, w indicates an integer of 2 to 20, and * indicates a bonding hand.

3. The charging member according to claim 2,

49 wherein the partial structure represented by Formula (I) is set as a monomer unit, and wherein a content of the monomer unit is approximately 5.0 mol% to 20.0 mol% relative to a total amount of monomer units included in the polysiloxane.

4. The charging member according to claim 1 , wherein the polysiloxane has a cross-linked structure derived from an epoxy group.

5. The charging member according to claim 1 , wherein the molecular structure of the polysiloxane has a Si-O-Zr bond.

6. The charging member according to claim 1 , wherein the coating layer comprises a cured product of a curable composition comprising: cross-linkable polysiloxane having a molecular structure comprising a Si-O-Ti bond and a TiCU/i unit, wherein the crosslinkable polysiloxane has an epoxy group as a cross-linkable group; and an acid generating agent.

7. The charging member according to claim 6, wherein the acid generating agent is a thermal-acid generating agent to be activated at a temperature of 250°C or less.

8. The charging member according to ciaim 6, wherein the acid generating agent is a photo-acid generating agent to be activated with light having a wavelength of 365 to 405 nm.

9. The charging member according to claim 1 , wherein a thickness of the coating layer is approximately 50 to 500 nm.

10. The charging member according to claim 1 , wherein the resin layer comprises a matrix material, and particles dispersed in the matrix material.

11 . The charging member according to claim 10, wherein the particles comprise first particles, and second particles having a type different from a type of the first particles.

12. A method of manufacturing a charging member, the method comprising: applying a coating liquid comprising a curable composition onto a surface of a conductive base that is mountable on a conductive support, wherein the curable composition comprises cross-linkable polysiloxane having a molecular structure comprising a Si-O-Ti bond and a TIO4/1 unit, and an acid generating agent, wherein the cross-linkable polysiloxane has an epoxy group, as a cross-linkable group,

51 wherein the conductive base comprises an elastic layer, and a resin layer located on the elastic layer, and wherein the resin layer forms the surface to which the coating liquid is applied; and forming a coating layer on the conductive base by curing the curable composition.

13. The method of manufacturing according to claim 12, wherein the molecular structure of the cross-linkable polysiloxane has a partial structure comprising the TiCU/i unit, wherein the partial structure is defined according to a Formula (I) represented by: wherein each R^a independently indicates a monovalent hydrocarbon group, w indicates an integer of 2 to 20, and * indicates a bonding hand.

14. The method of manufacturing according to claim 12, wherein the molecular structure of the cross-linkable polysiloxane has a Si-O-Zr bond.

15. An image forming apparatus, comprising: a photoreceptor; and a charging member to charge the photoreceptor, wherein the charging member comprises: a conductive support; and a conductive body mounted on the conductive support, wherein the conductive body comprises: an elastic layer located on the conductive support; a resin layer located on the elastic layer; and a coating layer located on the resin layer, wherein the coating layer comprises polysiloxane having a molecular structure comprising a Si-O-Ti bond and a TIO4/1 unit.